Thin wire/thick wire lead assembly for electrolytic capacitor

Patent metadata

Field	Value
Publication number	US-9269499-B2
Application number	US-201313972987-A
Country	US
Kind code	B2
Filing date	Aug 22, 2013
Priority date	Aug 22, 2013
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A capacitor containing a solid electrolytic capacitor element including a sintered porous anode body, a first anode lead, and a second anode lead is provided. The first anode lead has a thickness that is larger than a thickness of the second anode lead. A portion of the first anode lead is embedded in the porous anode body, and a second portion of the first anode lead extends from a surface thereof in a longitudinal direction. Meanwhile, the second anode lead is electrically connected to the anode body for connection to an anode termination. In one embodiment, the second anode lead can be directly connected to a surface of the anode body. In another embodiment, the second anode lead can be indirectly connected to the anode body such as via attachment at an end of the second portion of the first anode lead.

First claim

What is claimed is:

1. A solid electrolytic capacitor that comprises a capacitor element, the capacitor element comprising:
a sintered, porous anode body;
a first anode lead, wherein a first portion of the first anode lead is embedded within the porous anode body and a second portion of the first anode lead extends from a surface of the porous anode body in a longitudinal direction;
a second anode lead, wherein the second anode lead is positioned external to the porous anode body, further wherein the second anode lead is not embedded within the porous anode body;
a dielectric layer overlying the sintered porous anode body; and
a cathode overlying the dielectric layer that includes a solid electrolyte.

2. The solid electrolytic capacitor of claim 1 , wherein the second anode lead has a thickness that is smaller than the thickness of the first anode lead.

3. The solid electrolytic capacitor of claim 2 , wherein the thickness of the second anode lead is from about 10% to about 90% of the thickness of the first anode lead.

4. The solid electrolytic capacitor of claim 2 , wherein the thickness of the first anode lead is from about 100 micrometers to about 2000 micrometers.

5. The solid electrolytic capacitor of claim 2 , wherein the thickness of the second anode lead is from 10 micrometers to about 1800 micrometers.

6. The solid electrolytic capacitor of claim 2 , wherein the first anode lead and the second anode lead are the same material.

7. The solid electrolytic capacitor of claim 2 , wherein the first anode lead and the second anode lead are different materials.

8. The solid electrolytic capacitor of claim 1 , wherein the first anode lead is a different material than the second anode lead, further wherein the second anode lead has a thickness that is the same as or larger than the thickness of the first anode lead.

9. The solid electrolytic capacitor of claim 1 , wherein the second anode lead is connected to the surface of the porous anode body such that the second anode lead is adjacent to and in contact with the second portion of the first anode lead.

10. The solid electrolytic capacitor of claim 9 , wherein the second anode lead is connected to the surface of the porous anode body by resistance welding.

11. The solid electrolytic capacitor of claim 9 , wherein the second anode lead is connected to the surface of the porous anode body by laser welding.

12. The solid electrolytic capacitor of claim 1 , wherein the second anode lead is connected to the second portion of the first anode lead.

13. The solid electrolytic capacitor of claim 12 , wherein the second anode lead extends beyond the second portion of the first anode lead in a longitudinal direction.

14. The solid electrolytic capacitor of claim 12 , wherein the second anode lead is connected to the second portion of the first anode lead by resistance welding.

15. The solid electrolytic capacitor of claim 12 , wherein the second anode lead is connected to the second portion of the first anode lead by laser welding.

16. The solid electrolytic capacitor of claim 1 , wherein the anode body is formed from a powder having a specific charge of from about 10,000 ρF*V/g to about 600,000 ρF*V/g, wherein the powder comprises a valve metal such as tantalum, niobium, aluminum, hafnium, titanium, an electrically conductive oxide thereof, or an electrically conductive nitride thereof.

17. The solid electrolytic capacitor of claim 1 , further comprising an anode termination that is electrically connected to the second anode lead and a cathode termination that is electrically connected to the cathode.

18. A method for forming a solid electrolytic capacitor comprising a sintered, porous anode body, the method comprising:
positioning a first portion of a first anode lead within a powder formed from a valve metal composition such that a second portion of the first anode lead extends from a surface of the anode body in a longitudinal direction;
compacting the powder around the first portion of the first anode lead;
sintering the compacted powder and the first portion of the first anode lead to form the porous anode body;
positioning a second anode lead external to the porous anode body; and
welding the second anode lead to an anode termination to form an electrical connection between the second anode lead and the anode termination.

19. The method of claim 18 , wherein the second anode lead is connected to the surface of the porous anode body such that the second anode lead is adjacent to and in contact with the second portion of the first anode lead, wherein the second portion of the first anode lead is also welded to the anode termination.

20. The method of claim 19 , wherein the second anode lead is welded to the surface of the porous anode body.

21. The method of claim 18 , wherein the second anode lead is connected to the second portion of the first anode lead.

22. The method of claim 21 , wherein the second anode lead is extends beyond the second portion of the first anode lead in a longitudinal direction.

23. The method of claim 21 , wherein the second anode lead is welded to the second portion of the first anode lead.

24. The method of claim 18 , further comprising trimming the second anode lead.

25. The method of claim 18 , further comprising:
anodically oxidizing the sintered, porous anode body to form a dielectric layer; and
applying a solid electrolyte to the anodically oxidized sintered anode body to form a cathode.

26. The method of claim 25 , further comprising:
forming an electrical connection between the cathode and a cathode termination; and
encapsulating the capacitor with a molding material such that at least a part of the anode termination and a part of the cathode termination remain exposed.

27. The method of claim 18 , wherein the second anode lead has a thickness that is smaller than the thickness of the first anode lead.

28. The method of claim 27 , wherein the first anode lead and the second anode lead are the same material.

29. The method of claim 27 , wherein the first anode lead and the second anode lead are different materials.

30. The method of claim 18 , wherein the first anode lead is a different material than the second anode lead, further wherein the second anode lead has a thickness that is the same as or larger than the thickness of the first anode lead.

Assignees

• Avx Corp

Inventors

• Djebara Lotfi
• Zednicek Stanislav
• Horacek Ivan
• Petrzilek Jan

Classifications

• H01G9/052

  Sintered electrodes · CPC title

• H01G9/0525 Primary

  Powder therefor · CPC title

• H01G9/025

  Solid electrolytes (H01G11/54 takes precedence) · CPC title

• H01G9/0029

  Processes of manufacture · CPC title

• H01G9/15 Primary

  Solid electrolytic capacitors (H01G11/00 takes precedence) · CPC title